MCB 461 Final Exam Questions And Answers Newest
RATED A+ 2025/2026 UPDATED
How does binocular vision develop before birth? - Answers Thalamic inputs representing the
left and right eyes segregate from each other to form "ocular dominance" columns of roughly
equal width in the visual cortex
How does binocular vision develop soon after birth? - Answers During the critical period, the
visual experience shapes and combines the representations of the 2 eyes in the cortex to make
binocular vision possible
Normal binocular vision consolidates and refines the established patterns of ocular
representation
Depends on correlated patterns of activity from 2 eyes and convergence of inputs from Layer IV
to III
What happens if you perform monocular deprivation during the critical period? - Answers
The LGN axons from the deprived eye in layer 4 will shrink and decrease in synaptic strength,
whereas axons from the non-deprived eye expand and increase in synaptic strength
What happens if you reinstate normal vision during monocular deprivatioN? - Answers This
does not readily restore normal binocular responses in the cortex.
The non deprived eye continues to dominate the responses of cortical neurons (even up to 5
years)
A critical period of binocular vision - Answers A "critical period" to establish binocular
receptor fields
Effects of disruptions of binocular vision are IRREVERSIBLE when they occur in the critical
period. In cats, this begins rapidly at 3 weeks. After 6 weeks, this period gradually closes.
,What are some mechanisms of binocular plasticity? - Answers Modulation of LGN axons that
project to layer 4
Adjust synaptic drive by the left and right eyes (NMDA receptor activation)
Mechanisms that contribute to synapse formation or stabilization (BDNF, neuromodulators—
acetylcholine, norepinephrine)
PirB or Nogo and its receptors
Precise balance between excitatory and inhibitory inputs
Critical period is delayed in GABAA receptor knock out mice
Dark rearing prolongs the critical period
Hebbian plasticity - Answers Persistent activation of a group of simultaneously active neurons
would lead to consolidation of stronger connection
In response to extrinsic stimuli, neurons can change and adapt the strength of their
connections. Examples are long term potentiation (LTP) and long term depression (LTD)
Hebbian Plasticity is - Answers Associative
Rapidly induced
Input specific
Positive feedback process
Physiological relevance
Cellular correlate of "learning and memory"
Where does Hebbian synaptic plasticity happen? - Answers The HIPPOCAMPUS
LTP and LTD are key to forming declarative memories in the brain
, Pathway from entorhinal cortex - Answers Goes from pyramidal cells in the dentate gyrus to
pyramidal cells in CA3 to pyramidal cells in CA1
Synaptic plasticity in the hippocampus is the key to forming - Answers Declarative memories
in the brain
LTP happens at glutamatergic synapses in hippocampus: discovered by - Answers Bliss and
Lomo
Dark circles: POTENTIATED, and their amplitude is higher
In the hippocampus, the EPSP magnitude during LTP - Answers Increases
In the hippocampus, the EPSP magnitude during LTD - Answers Decreases
What's the problem with Hebbian platicity - Answers Eventually, persistently activating
neuronal networks would reach an extreme and become unstable
Homeostatic plasticity - Answers Rapid or prolonged process to maintain neuronal firing and
synaptic strength *within physiological limit*, thereby preventing un-restrained increases or
decreases in neuronal activity
How does homeostatic plasticity work - Answers Induced rapidly or in a long term
Global but unequal scaling
Homeostatic negative feedback process
Physiological relevance (Developmental regulation, intraoccular injection of TTX or dark rearing)
Excitatory inhibitory balance in Vivo
Connection specific regulation (TTX effect on CA3-CA1 versus CA3 CA3_
Abnormal plasticity in disease mechanism
RATED A+ 2025/2026 UPDATED
How does binocular vision develop before birth? - Answers Thalamic inputs representing the
left and right eyes segregate from each other to form "ocular dominance" columns of roughly
equal width in the visual cortex
How does binocular vision develop soon after birth? - Answers During the critical period, the
visual experience shapes and combines the representations of the 2 eyes in the cortex to make
binocular vision possible
Normal binocular vision consolidates and refines the established patterns of ocular
representation
Depends on correlated patterns of activity from 2 eyes and convergence of inputs from Layer IV
to III
What happens if you perform monocular deprivation during the critical period? - Answers
The LGN axons from the deprived eye in layer 4 will shrink and decrease in synaptic strength,
whereas axons from the non-deprived eye expand and increase in synaptic strength
What happens if you reinstate normal vision during monocular deprivatioN? - Answers This
does not readily restore normal binocular responses in the cortex.
The non deprived eye continues to dominate the responses of cortical neurons (even up to 5
years)
A critical period of binocular vision - Answers A "critical period" to establish binocular
receptor fields
Effects of disruptions of binocular vision are IRREVERSIBLE when they occur in the critical
period. In cats, this begins rapidly at 3 weeks. After 6 weeks, this period gradually closes.
,What are some mechanisms of binocular plasticity? - Answers Modulation of LGN axons that
project to layer 4
Adjust synaptic drive by the left and right eyes (NMDA receptor activation)
Mechanisms that contribute to synapse formation or stabilization (BDNF, neuromodulators—
acetylcholine, norepinephrine)
PirB or Nogo and its receptors
Precise balance between excitatory and inhibitory inputs
Critical period is delayed in GABAA receptor knock out mice
Dark rearing prolongs the critical period
Hebbian plasticity - Answers Persistent activation of a group of simultaneously active neurons
would lead to consolidation of stronger connection
In response to extrinsic stimuli, neurons can change and adapt the strength of their
connections. Examples are long term potentiation (LTP) and long term depression (LTD)
Hebbian Plasticity is - Answers Associative
Rapidly induced
Input specific
Positive feedback process
Physiological relevance
Cellular correlate of "learning and memory"
Where does Hebbian synaptic plasticity happen? - Answers The HIPPOCAMPUS
LTP and LTD are key to forming declarative memories in the brain
, Pathway from entorhinal cortex - Answers Goes from pyramidal cells in the dentate gyrus to
pyramidal cells in CA3 to pyramidal cells in CA1
Synaptic plasticity in the hippocampus is the key to forming - Answers Declarative memories
in the brain
LTP happens at glutamatergic synapses in hippocampus: discovered by - Answers Bliss and
Lomo
Dark circles: POTENTIATED, and their amplitude is higher
In the hippocampus, the EPSP magnitude during LTP - Answers Increases
In the hippocampus, the EPSP magnitude during LTD - Answers Decreases
What's the problem with Hebbian platicity - Answers Eventually, persistently activating
neuronal networks would reach an extreme and become unstable
Homeostatic plasticity - Answers Rapid or prolonged process to maintain neuronal firing and
synaptic strength *within physiological limit*, thereby preventing un-restrained increases or
decreases in neuronal activity
How does homeostatic plasticity work - Answers Induced rapidly or in a long term
Global but unequal scaling
Homeostatic negative feedback process
Physiological relevance (Developmental regulation, intraoccular injection of TTX or dark rearing)
Excitatory inhibitory balance in Vivo
Connection specific regulation (TTX effect on CA3-CA1 versus CA3 CA3_
Abnormal plasticity in disease mechanism
